Spun yarn



July 30, 1968 E. E. NEFF 3,394,538

SPUN YARN Filed Jan. 14, 1966 FIGI INVENTOR ATTORNEY United StatesPatent 3,394,538 SPUN YARN Eugene E. Neif, Charlotte, N.C., assignor toCelanese Corporation of America, New York, N.Y., a corporation ofDelaware Filed Jan. 14, 1966, Ser. No. 520,692 Claims. (Cl. 5738.3)

ABSTRACT OF THE DISCLOSURE A method and apparatus for spinning noveltyyarn by feeding a plurality of staple fiber rovings separately throughdrafting means including a pair of front rolls, the front rollsalternately nipping and releasing at least one of the rovings so as tovary both the drafting action on such roving and the relative rates ofdelivery of the roving into the twisting zone thereby producing a thickand thin novelty yarn.

This invention relates to a novel spun yarn having random thick and thinsections along its length and a method and apparatus for producing suchyarn.

Yarns having thick and thin sections have long been known to the art.When incorporated into fabrics, as by weaving, such yarns provideinteresting texture effects, enhancing the appearance and feel of thefabrics and increasing their suitability for certain end uses. Forexample, many garment fabrics and drapery fabrics embody such yarns.

One known type of thick-and-thin yarn is produced customarily bycombining two already spun yarns on a novelty twister in such a way thatthick sections are formed periodically by wrapping one of the yarnsloosely about the other. An example of an early disclosure dealing withsuch a technique is the United States Patent Number 386,623 granted onJuly 24, 1888.

For some applications a degree of irregularity in the thiek-and-thinyarn sections is highly desirable. When yarns having regularly spaced,uniform thick sections are woven into fabric, the fabric usually willhave a line or rowed pattern effect that detracts from the overallappearance.

An object of this invention is to provide a novelty yarn having thickand thin sections of irregular lengths and thicknesses. Another objectof this invention is to provide a method and apparatus for economicallyproducing a novelty yarn directly from rovings on a conventional textilemachine with only slight modifications to the structure of the machine.

These objects are accomplished in accordance with a preferred embodimentof the invention by alternately drafting and releasing separate rovingsas they are being spun together. Preferably, the spinning is carried outin a conventional worsted ring spinning frame that includes draftingrolls and means for twisting the rovings together as they emerge fromthe drafting rolls. In the apparatus of this invention, one of the rollsin the last pair of drafting rolls, the top front roll, is provided withaxially spaced roll sections each of which separately engages one of therovings. The sections of the modified top front roll have recesses intheir cylindrical surfaces and the recesses in one section are offsetangularly from corresponding recesses in the other roll section. Therovings are spun together under tension after passing between the frontrolls.

The configuration of the top front roll is such that, during rotation ofthe roll, each of the rovings is alternately pressed against the bottomfront roll and released from driving engagement with such roll. When aroving is being pressed against the bottom front roll, both 3,394,538Patented July 30, 1968 the rate of delivery of the roving to thetwisting means and the degree of draft imparted to the roving aredetermined by the surface speed of the bottom front roll. However, whena roving is disposed between the bottom front roll and a recessedportion of the top front roll, the fibers thereof need not move at thesurface speed of the bottom front roll, so that neither rate of deliveryto the twister head nor degree of draft is a direct function of bottomfront roll speed.

As two rovings pass together through the apparatus a number of differenteffects are produced. At one moment both of the rovings may be pressedagainst the bottom front roll. At other moments one or the other of therovings may be opposite recessed portions of the top roll. When oneroving is being pressed against the bottom front roll and the other isnot, differential drafting occurs along with a wrapping and looping ofthe one roving about the other due to their different rates of deliveryto the twisting head. These various effects interact in an unpredictableway and the end result is a yarn having thick and thin sections that arerandom in the sense of being unpredictable as to length and bulk.

A preferred embodiment of the invention is illustrated in theaccompanying drawings in which:

FIGURE 1 is a side elevational view of a worsted spinning frameincorporating the apparatus of the invention;

FIGURE 2 is a front elevational frame;

FIGURE 3 is an enlarged vertical cross sectional view of the front rollsof the spinning frame along the line 33 in FIGURE 4;

FIGURE 4 is a front elevational view of the front rolls; and

FIGURE 5 is a schematic view of a fabric having a plurality of yarns inaccordance with this invention woven therein.

Referring to FIGURES l and 2, a conventional worsted ring spinning frameincludes a creel 2 in which are mounted supply packages 4 and 6 that arewound with rovings 8 and 10 of staple fibers. Rovings from the bobbins 4and 6 pass through separate guides indicated at 12 and into draftingmeans 14. The rovings emerging from the rolls of the drafting means 14pass through a yarn guide 16 and then to the ring traveller 18 of thespinning head. The twisted yarn is wound on a bobbin 20 mounted on aspindle 22 rotated by a motor driven tape or belt 24. As shown in FIGURE2, the rovings 8 and 10 follow separate paths through the set ofdrafting rolls and are twisted together by the rotating ring traveller18. The bobbin 20 applies tension to the yarn between the bobbin and thelast pair of rolls in the set of rolls 14. There are two completespinning units shown in FIGURE 2. Actually, many units are mountedside-by-side on a common frame.

The drafting means 14 includes a first pair of rolls, commonly calledback rolls 26 and 28, intermediate or middle rolls 30 and 32, and frontrolls 34 and 36. The lower roll of each pair is positively driven andthe top roll of each pair is pressed against the corresponding lowerroll so that it moves at the same surface speed. The front rolls 34 and36 move at a surface speed greater than that of the back rolls 26 and 28to provide for a drafting action on the rovings as the rovings movethrough the roll set.

In accordance with this invention, the front top roll 34 is generallycylindrical, but is divided into roll sections 38 and 40. The rollsection 38 has a pair of recesses 42 on opposite sides of the rollsection. The other roll section 40 has a pair of oppositely facingrecesses 44. The pairs of recesses 42 and 44 are angularly offset fromone another, as shown in FIGURE 3. Preferably,

view of the spinning they are offset approximately 90. Roving passesunder the roll section 38, as shown in FIGURE 4, and the other roving 8passes under the roll section 40. The ring traveller 18 causes therovings 8 and 10 to be twisted together as they emerge from between thefront rolls 34 and 36.

The roving 8 is not engaged by the top front roll 34 when the roll is inthe position shown in FIGURE 4. However, at the same time, the otherroving 10 is nipped between the top front roll and the bottom frontroll. The ring traveller 18 and the bobbin 20 apply tension to thedoubled yarn, but since the roving 8, which is twisted into the yarn, istemporarily released from engagement with the top front drafting roll,it is not fed toward the twisting head as rapidly as the other roving10. The twisting action of the ring 18, therefore, causes the roving 10to wrap around the roving 8, as shown at 46 in FIGURE 4. Because of therelatively large difference in the rates of delivery of the two rovings,a loose wrapping of the roving 10 occurs and in the relaxed yarn, loopsof the wrapping 10 protrude from the main body of the yarn in a boucleeffect.

The top and bottom front rolls are continuously rotating and after thetop roll 34 has rotated approximately 45 from the position shown inFIGURE 4, the cylindrical portion of the roll section 40 engages theroving 8 and then the other roving 10 is released as the recess 42 movesopposite the roll 36. When this occurs, the roving 8 is Wrapped aroundthe roving 10. Thus, successive thick sections in the yarn are formed byalternately wrapping one roving and then the other. The top rollrecesses are not angularly contiguous, but there are zones 48 where bothroll sections have full diameter cylindrical surface portions. When thezones 48 are in engagement with the rovings, they are both subjected tothe same drafting forces and both are fed to the twister at the samerate.

Although the recesses 42 and 44 release the respective rovings 8 and 10at regular intervals, the lengths and weights of the thick sections 46and their positions along the length of the twisted yarn are notuniform. The thick sections are formed randomly along the length of theyarn. This surprising result apparently stems from the interaction ofthe varying twist and draft effects which occur as the front top rollsections nip and release the rovings.

In FIGURE 5, several yarns 50, produced in accordance with thisinvention, are shown schematically as woven as the filling in a fabric.The lengths of the thick sections 52 are widely variable and thedistances between them are irregular. The thick sections also vary inbulk. Many of them appear as loosely twisted or wrapped structures,having discernible protruding loop portions 54.

As an additional feature of this invention, rovings of different colorsmight be used to produce alternately colored thick sections in the yarn.Since the surface fibers of the thick sections alternate between oneroving and the other along the yarn, successive thick sections would beof different colors. The same effect could be achieved by usingdifferent fibers in the rovings and cross-dyeing the fibers after theyarn is spun. Also, different fibers could be used to produce alternatethick sections having different characteristics.

While this invention has been illustrated and described in oneembodiment, it is recognized that variations and changes may be madetherein without departing from the invention as set forth in the claims.

What is claimed is:

1. In a method of spinning yarn in which a plurality of staple fiberrovings are fed separately through drafting means including a pair offront rolls and in which twisting forces are applied to the rovings asthey leave said front rolls to twist the rovings together into a yarn,the improvement which comprises alternately nipping and releasing atleast one of the rovings as it passes said front rolls so as to varyboth the drafting action on such roving and the relative rates ofdelivery of said rovings into the zone of application of the twistingforces to produce a novelty yarn random thick and thin sections alongits length.

2. A method according to claim 1 in which two rovings are alternatelynipped and released as they pass the front rolls, and in which thenipping of one of the rovings is out of phase with the nipping of theother of the rovrngs.

3. In a spinning frame means including a pair of front rolls fordrafting rovings, twisting means for receiving a pair of rovings fromsaid front rolls and applying twist thereto to form a composite yarn oneof said front rolls having axially spaced roll sections, means forguiding rovings individually between said front rolls with one of saidrovings engaging a first roll section and another of said rovingsengaging a second roll section, means for separating said roll sectionsfrom engagement with said rovings for periodic intervals alternatingbetween said first and second roll sections said separating meansincluding recesses in the circumferences of said roll sections, saidrecesses being angularly offset from each other and extending over lessthan of are on the surface of the respective first and second rollsections whereby yarns having irregular thick sections are formed.

4. Apparatus according to claim 3 wherein said periodic intervals are ofsubstantially equal duration.

5. Apparatus according to claim 3 wherein each of said roll sections hasa pair of recesses on opposite sides thereof, said recesses in one rollsection being offset subtantially 90 from the recesses in the other rollsection.

References Cited UNITED STATES PATENTS 2,931,090 4/1960 Field 57-9l3,105,349 10/1963 Palm et al. 5791 3,144,747 8/ 1964 Palm et al. 57-91FOREIGN PATENTS 525,257 1/ 1954 Belgium.

971,812 8/1950 France.

707,116 5/ 1941 Germany.

1,886 7/1886 Great Britain. 325,710 2/ 1930 Great Britain. 385,263 3/1930 Great Britain.

FRANK J. COHEN, Primary Examiner.

W. SCHROEDER, Assistant Examiner.

